The present invention is directed to novel 4-substituted amino-3-[3-alkylindoloamino-2-hydroxypropoxy]thiadiazole compounds which have antihypertensive and .beta.-adrenergic blocking activity.
Various chemical agents are available for treating hypertension in man and animals. One class of agents, known as .beta.-adrenergic blocking agents, affect cardiac, vascular and pulmonary functions and can be mild antihypertensives. Specifically, these agents have the capability of reducing heart rate, counteracting vasodepression and suppressing bronchodilation. .beta.-adrenergic blocking agents, their chemical structure and activity, are disclosed in "Clinical Pharmacology and Therapeutics" 10, 292-306 (1969). Various .beta.-adrenergic blocking agents are also described in the following patents: U.S. Pat. No. 3,048,387; U.S. Pat. No. 3,337,628; U.S. Pat. No. 3,655,663; U.S. Pat. No. 3,794,650; U.S. Pat. No. 3,832,470; U.S. Pat. No. 3,836,666; U.S. Pat. No. 3,850,945; U.S. Pat. No. 3,850,946; U.S. Pat. No. 3,850,947; U.S. Pat. No. 3,852,291; U.S. Pat. No. 4,143,983; U.S. Pat. No. 4,199,580; and British No. 1,194,548.
W. E. Kreighbaum et al. [J. Med. Chem., 23, 285-289 (1980)] disclose aryloxypropanolamine compounds, some of which exhibit antihypertensive activity by the combination of .beta.-adrenergic receptor antagonist activity with vasodilating action.
Where an antihypertensive agent acts principally via vasodilation, it may cause undersirable side effects such as substantially increased heart rate (tachycardia). This undesirable side effect can be modified by the presence of .beta.-adrenergic blockade in the molecule.